>From the keyboard of Mike Long:

> >>>Yes, pcvt is using delay(6) calls, why do you recommend 7 or higher ?
> >
> >>According to _The Undocumented PC_ by Frank Gilluwe (sp?) the spec for
> >>the PS/2's keyboard controller requires that there be a 7ms delay
> >>between accesses to the controller's status port and its control port.
> >
> >There's only one delay(6) in pcvt, and it's between accesses to the 
> >status port and the _data_ port.  What does the book say about the
> >data port?  Does it say something about delaying between accesses to
> >the control port and the status port?

The Undocumented PC (Frank van Gilluwe) says on page 273:

"Before reading any information from port 60h, the controller output buffer
 status should be checked to ensure a byte is available. Read port 64h to
 get the status and check that bit 0 is 1. If bit 0 is 0, then no valid 
 information is available. MCA systems with a type 1 controller must wait
 at least 7 microseconds after bit 0 transitions from 0 to 1 before reading
 the data from port 60h."

I have not found references to other delays which might be necessary.

Further down in the text is a code fragment to detect MCA type 1 and 2
motherboard controllers (!), it would be interesting to see the results
of running this fragment on the Gateway 2000 machines in question!

hellmuth
-- 
Hellmuth Michaelis        GFKT HCS Computertechnik GmbH        Hamburg, Europe
                     We all live in a yellow subroutine, yellow subroutine ...